Apparatus for interlacing continuous filaments

ABSTRACT

The specification discloses an apparatus for interlacing continuous filaments to form a yarn having a coherent structure, due to the action of at least one high velocity fluid jet. Extending through a main body member of the apparatus is a keyhole cross section passage having a cylindrical portion through which the filaments run, and an isosceles trapezoidal cross section prismatic portion into which the fluid jet is symmetrically projected.

United States Patent Inventor Michel Buzano Villeurbanne, (Rhone), France Appl. No. 779,781 Filed Nov. 29,1968 Patented Mar. 23, 1971 Assignee Societe Rhodiaceta Paris, France Priority Nov. 30, 1967 France 130,393

APPARATUS FOR INTERLACING CONTINUOUS FILAMENTS 7 Claims, 7 Drawing Figs.

US. Cl 28/ 1.4,

28/72.12 Int. Cl D02g 3/00 Field of Search Primary Examiner-Mervin Stein Attorney-Cushman, Darby & Cushman ABSTRACT: The specification discloses an apparatus for interlacing continuous filaments to form a yarn having a coherent structure, due to the action of at least one high velocity fluid jet. Extending through a main body member of the apparatus is a keyhole cross section passage having a cylindrical portion through which the filaments run, and an isosceles trapezoidal cross section prismatic portion into which the fluid jet is symmetrically projected.

PATENTEDHARZSIQYI 3,571,8

SHEET 1 OF 3 Inventor my Buzano B, wmmb wdvm A Home ys PATENTEDNARZBISTI 3571 868 SHEETEUF s x I nuenlor Ilkhel Buzano 8 OAs 'vmmflmb Chshm A llorneys PATENTEU mm SHEET 3 OF 3 V nven lor M 27. EUZAP/VO APPARATUS FOR ENTERLACKNG- CUNTHNUOTJS lFIlLAMlENTEi The present invention relates to apparatus for interlacing continuous filaments to form a yarn having a coherent structure.

In order to impart to a yarn cohesion and thus also satisfactory resistance to unraveling or fraying out, the yarn is conventionally subjected to a twisting operation the intensity of which varies more or less depending on the applications envisaged for the yarn. To improve the cohesion of the filaments, such twisting has been combined with a sizing operation. However, these twisting and sizing operations are lengthy and costly.

Thus, many attempts have been made to find a process permitting the production in a more economical manner of the same coherent structure. With continuous multifilament yarns, twisting and sizing are advantageously avoided by bonding the filaments together by interlacing and the resulting yarn structure constitutes an assembly of continuous multifilaments, wherein the elementary filaments of which it is composed are interlaced or tangled in purely randomfashion, so as to form pseudoknots" and in such manner as to constitute a yarn which is practically compact and which has a total twist which is substantially equal to zero, and the apparent volume of which is substantially the same as that of a yarn of the same count, having conventional twist and nonprocessed. In other words, the resulting yarn is characterized by smooth appearance, substantially free from peripheral loops, like a single-twist yarn.

The various known processes which have hitherto been proposed for producing such yarn all consist in subjecting the yarn, under a slight degree of tension and, while travelling between two yarn guides, to the action of at least one flow of fluid, notably to a jet of compressed air. in practice, the jet is directed in a plane substantially perpendicular to the direction of advance of the yarn.

in one process, the yarn is caused to travel between a nozzle or jet and a resonance chamber. in an improved process, the jet of fluid is recovered at the outlet of the resonance chamber and is caused to act once again on the yarn.

in a further process, the yarn is introduced into a zone of controlled turbulence wherein the axes of eddy rotation are substantially parallel to the direction of advance of the yarn.

A further process, disclosed in French Patent specification No. 1,492,945 consists in subjecting the yarn simultaneously to the action of atleast one pair of jets known as primary jets and at least a further jet known as a secondary jet acting on the yarn in a direction substantially opposite to that of the primary jets and in a zone located between the points of impact of the primary jets on the yarn. Advantageously, the secondary jet is formed by collecting and combining the primaryjets.

The known devices for the performance of these processes generally comprise a passage for the yarn, into which open the fluid nozzle or nozzles, which are arranged in a plane substantially perpendicular to the direction of advance of the yarn. The cross section of the yarn passage is circular, rectangular, V-shaped or trough-shaped.

it has been found that, with these types of yarn passages, the yarn tends momentarily, or even finally, to be deflected from its normal travel and thus to be shielded from the interlacing effect. in the yarn, this results on the one hand in a diminution in the degree of interlacing and on the other hand, above all, in the irregular spacing of the pseudoknots. Thus, these yams, while they may have an acceptable degree of interlacing, are generally unsatisfactory since, due to the considerable length of yarns without interlacing in these portions which lack cohesion, the elementary filaments tend to unravel or fray out. Furthermore, in use the interlacing apparatus tends to become clogged due to the accumulation, at predetermined points in the passage of the yarn, with particles entrained in the compressed air, with deposits of yarn finishing materials, and with low polymers. Thus, it has been found that for a constant flow rate of compressed air, the interlacing effect diminishesconsiderably in the long run.

According to the present invention there is provided an apparatus comprising a main body member having a passage therethrough, said passage including a cylindrical portion and an isosceles trapezoidal cross section prismatic portion connected thereto, with the axis of the cylindrical portion extending in the plane of symmetry of the isosceles trapezoidal cross section prismatic portion, and at least one fluid nozzle positioned to project at least one fluid jet into said isosceles trapezoidal cross section prismatic portion generally transversely to said axis and along said plane of symmetry.

ln an advantageous embodiment the passage also includes a rectangular cross section portion of said passage connecting said isosceles trapezoidal cross section prismatic portion designated hereinafter merely by trapezoidal portion to said cylindrical portion.

The apparatus according to the invention may also include means wherein said trapezoidal portion of said passage converges towards said cylindrical portion thereof.

Preferably, the trapezoidal portion is oricntated in such manner that it converges towards the cylindrical portion.

in order that the yarn may remain in the cylindrical portion and be effectively subjected to the interlacing effect, it is necessary that the yarn passage should exhibit a plane of axial symmetry and that the jets of fluid and the yarn should be in the plane of symmetry. it has been found that, if one of the portions, for example the cylindrical portion or the trapezoidal portion, is slightly offset relatively to the remainder of the passage, a parasite false twist is formed in the yarn. Furthermore, the yarn may be expelled from the cylindrical portion.

Furthermore, it is advantageous that the interlacing device may be formed with one or more axial slots connected to said trapezoidal portion at a location thereof remote from said cylindrical portion of said passage. An arrangement of this kind makes it possible to avoid excessive escape of fluid through the ends of the yarn passage. in this way, the yarn is prevented from being subjected to undesirable influences upstream and downstream of the main body member. In practice, the slots are arranged between the fluid feed ducts and the trapezoidal portion of the yarn passage. Preferably, the slots are disposed symmetrically relatively to the plane of axial symmetry of the assembly. At least one of the said slots facilitates the introduction of the yarn.

The shape of the yarn passage which is characteristic of the invention may be adapted to the majority of known interlacing devices wherein the fluid flow contacts the yarn in the passage. in this way, it becomes possible to design devices comprising one or more fluid inlets, which may or may not be inclined relatively to the direction of advance of the yarn, and which are or are not operative in the same direction, the fluid jets optionally being collected and combined so as to form a secondary jet.

The arrangement of the yarn passage according to the invention, i.e. having the said section practically speaking of keyhole" type, is particularly advantageous for the devices disclosed in French Pat. specification No. 1,492,945.

Due to its design the apparatus of the invention is self-centering, this property being immediate and permanent, so that the yarn immediately adopts its position in the cylindrical portion and remains there practically permanently. Thus, the yarn is constantly subjected to the effect of the fluid and the result of this is practically uniform interlacing wherein the pseudoknots are only slightly dispersed.

Furthermore, the apparatus is self-cleaning, so that it is possible to produce consistently uniformly interlaced yarns.

if the axial slots are provided over the entire length of the main body, at least on one side thereof, the introductionof the yarn is facilitated by the shape of the yarn passage. This feature is extremely advantageous for production work.

Apparatus according to the invention may be used for interlacing continuous filament yarns of widely varying origin. it is possible to process either single yarns, i.e. yarns of the same nature, or mixed yarns, i.e. yarns of different physical and/or chemical nature.

In order to achieve the interlacing, the yarn is slightly under tension during its passage within apparatus according to the invention. In practice, the tension applied during winding on is normally less than l.5 g./denier and preferably ranges between 0.03 and l g. per denier. Similarly, the fluid utilized is a hot or cold gas. preferably a gas such as nitrogen, or compressed air which is inert to the yarn under a pressure of 0.2 to bars gauge.

The diameter of the fluid feed ducts preferably ranges between 0.3 and 3 mm. It is recommended to adopt, for the cylindrical portion and for the long base of the trapezoidal portion, substantially the same value as the diameter of these ducts.

The interlacing devices according to the invention may be manufactured from any suitable materials, such as brass, stainless tempered steel, ceramic material, plastics material, and the elements more particularly subjected to wear may be fitted separately and may be made from tungsten carbide, for example.

In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 is a diagrammatic view of an installation for the interlacing of a multifilament yarn;

FIG. 2 is a similar view of a further form of such installation;

FIG. 3 is a longitudinal section through one embodiment of interlacing apparatus according to the invention;

FIG. 4 is a plan view of the apparatus of FIG. 3;

FIG. 5 is an enlarged section through the apparatus of FIGS. 3 and 4;

FIG. 6 is a longitudinal section through a second embodiment of interlacing apparatus according to the invention; and

FIG. 7 is an enlarged section through the apparatus of FIG. 6.

Referring to FIG. 1, continuous multifilament yarn which may be untwisted or only slightly twisted, is fed from a bobbin 1 by a feed roller 2 to an interlacing apparatus 3 according to the invention. The yarn passes over a deflecting yam guide 4 and is wound on at zero twist, for example by a cam and guide system 5.

Referring to FIG. 2, a multifilament, undrawn synthetic yarn, such as is received directly from spinning, i.e. before drawing and orientation, is fed from a bobbin 1A by a feed roller 2A and around a draw or snubbing pin 6 by a drawing or drafting roller 7, to an interlacing device 3A according to the invention. The yarn then passes through a yarn guide 8 to a ring and traveller 9 for winding-on to form a cop 10.

The apparatus shown diagrammatically in FIGS. 3, 4 and 5 is similar to that disclosed in French Patent specification No. l,492,945, but wherein the yarn passage is designed, in accordance with the invention. In this embodiment the yarn passage has a keyhole cross section.

A brass or stainless steel inlet body member 11 of rectangular parallelepipedonal shape is formed with a fluid inlet 12 opening into a chamber 13, from which extend two cylindrical convergent ducts 14, forming primary nozzles located substantially in the same plane and forming an acute angle between them. Adjacent the inlet body member 11 is a main body member 16 made generally from the same material as member 11 and also of rectangular parallelepipedonal shape.

Opposite and aligned with the ducts 14, member 16 is formed with two collecting ducts 17. The collecting ducts open out into a chamber 18 from which extends a cylindrical duct 19 forming a secondary nozzle located in the same plane as the ducts l4 and 17.

As can be seen clearly from FIGS. 3, 4 and 5 a yarn passage 20 for the yarn extends through the main body member 16, and yarn is guided therethrough by yarn guides 21 at each end thereof. The yarn passage 20 include a substantially cylindrical portion 24 and an isosceles trapezoidal portion 22, the plane of symmetry 22A of which includes the axis 24A of the cylindrical portion 24, the walls of the portion 22 converging towards the portion 24. Connecting the portions 22 and 24 is a portion 23, which is rectangular in cross section, being symmetrical with respect to the plane 22A and cutting the cylindrical portion 24. At the wider end of the portion 22, i.e. the end remote from the cylindrical portion 24, lateral axially extending slots 15, 15A are provided. A connecting part 26 of inlet member 11 is 'used in securing the members 11 and 16 together.

The ducts l4, l7 and 19 all lie in the same plane, i.e. in the plane 22A, and gas introduced into inlet 12 is projected as primary jets by the nozzles formed by ducts 14, along the plane of symmetry into portion 23. The gas flows through portion 23 into portion 24 and some of the gas is collected by ducts l7 and combined in chamber 18, before being projected by the nozzle formed by duct 19, as a secondary jet, into the portion 24 at an axial location between the primary jets. The yarn, slightly tensioned, is introduced into the passage 20 via the lateral slot 15 and is guided, during functioning, by the yarn guides 21 disposed at each end of the passage 20.

The following examples illustrate the use of the above described apparatus. In these examples, the interlacing degree" is measured by the conventional method known as the hook" method, described for example in French Patent specification No. 1,305,832 of DU PONT de NEMOURS or in French Pat. specification No. 1,492,945.

EXAMPLE I The installation of FIG. 1 was utilized for processing a polyhexamethyleneadipamide (nylon 6.6) yarn wound-on under a tension of 0.07 g./denier, measured on the yarn downstream of the processing device at a velocity of approximately 600 meters/min.

The apparatus shown in FIGS. 3, 4 and 5 was constructed to having the following dimensions:

Overall length (l)=3l mm.

Overall height (h)=20 mm.

Overall width (w)=20 mm.

Diameter of ducts 14 1 .0 mm.

Diameter of ducts 17, 19 1 .2 mm.

Angle (a) between ducts 14 and 17 and duct 19=20 Dimension of passage 20 (i) total length (a)=2.0 mm.

(ii) length (e) of portion 22=0.7 mm.

(iii) length (I) of portion 23=0.4 mm.

(iv) base (b) of portion 22 .l mm.

(v) width (0) of portion 23=0.4 mm.

(vi) diameter (d) of portion 24--l .0 mm.

(vii) width (g) ofslots l5, 15A= 0.5 mm.

This interlacing apparatus was fed at various pressures, at the same time effecting a plurality of tests respectively on nylon 6.6 yarns, without twist, 7O denier/23 filament, delustred with 0.3 percent of titanium oxide, so-called semimatt quality, 70 denier/34 filament (semimatt) and 40 denier/l3 filament, (semimatt). The results are shown in the following table:

Degree of interlacing 70 d/231. 70 11/34 f. 40 d/13 1.

Relative pressure of compressed air,

in bars:

and the yarn tended to be withdrawn from the action of the fluid, so that finally the treated yarn exhibited certain zones which are practically without pseudoknots, whereas the average degree of interlacing was 12.2. When this yarn was used for weaving, it had atroublesome tendency to fray out or unravel.

EXAMPLE 2 EXAMPLE 3 On the assembly shown in FIG. 2, the same interlacing apparatus according to the invention is used as in Example 1 The winding-on spindle rotated at a velocity of 7700 r.p.m. The tension applied to the yarn was approximately 0.07 g./denier and the winding-on velocity was approximately 530 meters/min. The fluid feeding the device was compressed air at 5.5 bars gauge. A nylon 6.6, 40 denier/l3 filament, (semimatt) yarn, without twist, was processed.

The processed yarn was interlaced extremely uniformly and regularly. lt exhibited a degree of interlacing of 16.0.

EXAMPLE 4 Example 3 was repeated, utilizing an interlacing apparatus wherein the ducts l7, l8 and 19 of the rear portion 16 had been blocked or plugged. Such a construction is illustrated in FIGS. 6 and 7. lt will be noted that the ducts 14 again lie in the plane 22A, so that the gas introduced into the inlet 12 is projected as jets by the nozzles formed by the ducts 14 along the plane of symmetry of the portion 23. In this construction, the wall of the portion 24 opposite the portion 23 is of an uninterrupted cylindrical form.

The yarn obtained was interlaced with uniformity and exhibited a degree of interlacing of 15.0.

EXAMPLE 5 Example 3 was repeated except that the ducts l7 and 18 were blocked or plugged and wherein the duct 19 was directly connected to a source of compressed air (not shown).

All these ducts or conduits were fed at the same pressure of 5.5 bars.

As before the treated yarn was uniformly interlaced, and exhibited a degree of interlacing of l4.5.

I claim:

T. Apparatus for interlacing continuous filaments, said apparatus comprising, in combination:

a. a main body member;

b. means defining a generally keyhole shaped cross section passage through said body member for said filaments;

c. a cylindrical portion in said passage, said cylindrical portion having an axis;

d. an isosceles trapezoidal cross section prismatic portion in said passage converging towards and connected to said cylindrical portion, said isosceles trapezoidal cross section prismatic portion having a plane of symmetry in which said axis lies, the longitudinal axis of the prismatic portion being parallel to said axis;

e. at least one fluid nozzle effective to project at least one fluid jet into said isosceles trapezoidal cross section prismatic portion, generally transverse to said axis and along said plane of symmetry, the narrower dimension of said prismatic portion perpendicular to said plane being less than the diameter of said cylindrical portion, and lying between the fluid nozzle and the axis of the cylindrical portion. a

2. Apparatus for interlacing continuous filaments as claimed in claim 1, and further comprising a rectangular cross section portion in said passage connecting said isosceles trapezoidal cross section prismatic portion to said cylindrical portion thereof 3. Apparatus for interlacing continuous filaments as claimed in claim ll, and including means for projecting at least one fluid jet into said cylindrical portion of said passage from the side thereof opposite to said isosceles trapezoidal cross section prismatic portion.

4. Apparatus. for interlacing continuous filaments as claimed in claim 1, and including two primary fluid nozzles effective to project two primary fluid jets into said isosceles trapezoidal cross section prismatic portion, generally transversely to said axis and along said plane of symmetry, said nozzles being axially spaced apart from one another, with respect to said cylindrical portion, means defining collecting ducts in said main body member effective to collect and combine at least some of the fluid projected by-each of said primary fluid nozzles, and a means defining secondary nozzle in said body connected to said collecting ducts effective to project a secondary fluid jet into said cylindrical portion on the side thereof opposite said isosceles trapezoidal cross section prismatic portion, and axially between said primary fluid jets.

5. Apparatus for interlacing continuous filaments as claimed in claim 4, wherein said two primary fluid nozzles are disposed effective to project the two primary fluid jets converging towards one another.

6. Apparatus for interlacing continuous filaments as claimed in claim 1, and further comprising means defining at least one axial slot in said main body member, said at least one axial slot being connected to saidisosceles trapezoidal cross section prismatic portion at a location thereof remote from said cylindrical portion of said passage.

7. Apparatus for interlacing continuous filaments as claimed in claim I, and further comprising a rectangular cross section portion to said passage connecting said isosceles trapezoidal cross section prismatic portion to said cylindrical portion thereof, an uninterrupted cylindrical wall surface of said cylindrical portion being opposite said rectangular cross section portion, and two fluid nozzles, effective to project two fluid jets into said isosceles trapezoidal cross section prismatic portion, generally transversely to said axis, converging towards one another, and along said plane of symmetry, said fluid nozzles being axially spaced apart from one another, with respect to said cylindrical portion. 

1. Apparatus for interlacing continuous filaments, said apparatus comprising, in combination: a. a main body member; b. means defining a generally keyhole shaped cross section passage through said body mEmber for said filaments; c. a cylindrical portion in said passage, said cylindrical portion having an axis; d. an isosceles trapezoidal cross section prismatic portion in said passage converging towards and connected to said cylindrical portion, said isosceles trapezoidal cross section prismatic portion having a plane of symmetry in which said axis lies, the longitudinal axis of the prismatic portion being parallel to said axis; e. at least one fluid nozzle effective to project at least one fluid jet into said isosceles trapezoidal cross section prismatic portion, generally transverse to said axis and along said plane of symmetry, the narrower dimension of said prismatic portion perpendicular to said plane being less than the diameter of said cylindrical portion, and lying between the fluid nozzle and the axis of the cylindrical portion.
 2. Apparatus for interlacing continuous filaments as claimed in claim 1, and further comprising a rectangular cross section portion in said passage connecting said isosceles trapezoidal cross section prismatic portion to said cylindrical portion thereof.
 3. Apparatus for interlacing continuous filaments as claimed in claim 1, and including means for projecting at least one fluid jet into said cylindrical portion of said passage from the side thereof opposite to said isosceles trapezoidal cross section prismatic portion.
 4. Apparatus for interlacing continuous filaments as claimed in claim 1, and including two primary fluid nozzles effective to project two primary fluid jets into said isosceles trapezoidal cross section prismatic portion, generally transversely to said axis and along said plane of symmetry, said nozzles being axially spaced apart from one another, with respect to said cylindrical portion, means defining collecting ducts in said main body member effective to collect and combine at least some of the fluid projected by each of said primary fluid nozzles, and a means defining secondary nozzle in said body connected to said collecting ducts effective to project a secondary fluid jet into said cylindrical portion on the side thereof opposite said isosceles trapezoidal cross section prismatic portion, and axially between said primary fluid jets.
 5. Apparatus for interlacing continuous filaments as claimed in claim 4, wherein said two primary fluid nozzles are disposed effective to project the two primary fluid jets converging towards one another.
 6. Apparatus for interlacing continuous filaments as claimed in claim 1, and further comprising means defining at least one axial slot in said main body member, said at least one axial slot being connected to said isosceles trapezoidal cross section prismatic portion at a location thereof remote from said cylindrical portion of said passage.
 7. Apparatus for interlacing continuous filaments as claimed in claim 1, and further comprising a rectangular cross section portion to said passage connecting said isosceles trapezoidal cross section prismatic portion to said cylindrical portion thereof, an uninterrupted cylindrical wall surface of said cylindrical portion being opposite said rectangular cross section portion, and two fluid nozzles, effective to project two fluid jets into said isosceles trapezoidal cross section prismatic portion, generally transversely to said axis, converging towards one another, and along said plane of symmetry, said fluid nozzles being axially spaced apart from one another, with respect to said cylindrical portion. 